CN1654172A - Handheld tool machine - Google Patents

Abstract

The invention relates to a hand-held power tool with a hammer mechanism (40) and a clutch device (20), which can be engaged and disengaged for establishing and disengaging a drive connection (54) of the hammer mechanism (40). The invention proposes that at least a part of a drive bearing (18) is designed to be swivelable from an idle position into an impact position.

Description

hand tool machine

technical field

The invention relates to a hand-held power tool with a hammer mechanism and a clutch device which can be engaged and disengaged for establishing and disengaging the drive connection of the hammer mechanism.

Background technique

Hammer drills and/or chisel hammers are known which have pneumatic percussion mechanisms which can be switched on and off via a mechanical friction clutch. If a hammer drill and/or chisel hammer with a tool is pressed against a surface to be machined, a tool holder holding the tool is fed into the housing of the hammer drill and/or chisel hammer in the direction of the operator middle. Here, the conical friction surfaces of the friction clutch come into contact, while the pneumatic percussion mechanism is driven via a power train connection. During operation, the percussion mechanism generates a compressed air cushion via a piston, which can move axially in a cylinder, and the compressed air cushion accelerates a percussion element axially towards a percussion bolt. The striker strikes the striker stud, which thus acquires an impulse. This impulse is passed on to the tool in the tool holder.

If the hammer drill and/or chisel hammer with the tool is lifted from the machining surface, the friction surfaces of the friction clutch separate, thereby disconnecting the drive connection of the hammer mechanism.

Contents of the invention

The invention relates to a hand-held power tool with a hammer mechanism and a coupling device, which forms a drive connection to the hammer mechanism that can be engaged and disengaged. The invention proposes that at least some of the drive bearings are designed to be swivelable from an idle position into an impact position. The transition from the freewheeling position to the striking position can take place steplessly. In the idling position, the drive bearing is preferably approximately perpendicular to the axis of rotation of an intermediate shaft, so that the hand-held power tool runs almost vibration-free and runs smoothly during idling. In fact, a tool in the tool holder requires no or only a small free-running stroke. In this way, a very long service life with little wear to the tool holder can be achieved.

If the clutch element forms a support of the drive bearing at least in a partial area in the striking position, the actuating force can be adjusted via a contact surface. Expediently, the clutch element is mounted axially displaceable relative to the drive bearing. In order to generate the impact position, the clutch element can engage in the drive bearing. In this case, the pivoting movement of a pivot drive supports the pivoting of the drive bearing from the idle position into the striking position. An advantageous start-up behavior of the percussion mechanism can be achieved, since it is possible to accelerate from zero in the idling position to an operating frequency in the percussion position.

If the support structure of the drive bearing is designed to be conically constricted, the actuating force can be controlled and adjusted via the cone. The support is preferably integral with the clutch element. Alternatively, the support can also be separated from the clutch element. The construction of the clutch device is very short and compact, resulting in a short machine construction length. Clutches consist of only a small number of individual components. The production of the drive bearing, in particular of the pivot drive, is simplified. Complicated grinding of the oblique ball orbits required to provide the pivot angle can be dispensed with since the necessary pivot angle can be achieved by the cone of the coupling element. The inclined position of the drive bearing increases with the engagement stroke of the clutch element and enables gentle starting and stopping of the drive mechanism. When the impact mechanism is compressed, the drive bearing is pressed in the direction of one of the rotor shafts and takes up the force via the cone of the clutch element. In this way, the forces are resolved into an axial component and a radial component. The operator only feels the effect of the axial component. This part is small, so the operator only needs to apply a weak compression force.

If the drive bearing has a surface corresponding to the support, it is possible to pivot the drive bearing in a defined manner and support it securely. Enables a strong form-fit connection between support and drive bearing.

If the drive bearing is sunk into a driven spur gear at least in the impact position so as to face away from a support of the drive bearing via a toothed coupling, it is possible to connect via a positive fit between the drive bearing and the spur gear, Achieve slip-free rotation transmission. Alternatively, a corresponding form-fit connection to an intermediate shaft is also possible, which likewise enables a slip-free transmission of rotation.

If the clutch element is arranged on an intermediate shaft, a compact and low-construction clutch device can be obtained. Preferably, a rotary drive is arranged between the coupling element and the intermediate shaft, the latter being formed by rolling bodies connected in a stationary manner to the intermediate shaft. Preferably, balls are used as rolling bodies. Optionally, roller-shaped rolling elements can also be used.

If the clutch element is axially rigidly coupled to a hammer tube, it is possible to move the clutch element away from the machining surface when the tool is pressed against the machining surface.

The drive bearing can be pivoted into the free-running position by means of a free-running spring in that the free-running spring expands when the tool is released from the machining surface, thereby pressing the clutch element and a slip sleeve away, The lost motion spring is arranged between an annular projection of the slip sleeve and an annular projection of the clutch element. It is advantageous if the sliding sleeve is arranged axially fixed in the region of the drive bearing.

Vibration-free freewheeling of the hand-held power tool in the freewheeling position can be achieved if the drive bearing has a ball orbit running perpendicularly to the longitudinal axis of the drive bearing. The drive bearing can be perpendicular to the intermediate shaft in the idling position, so that the longitudinal axis coincides with the axis of rotation of the intermediate shaft. The machining of the drive bearing is simplified since the machining of the inclined ball raceway can be omitted. The required pivot angle can be adjusted automatically via the cone angle of the clutch element.

Furthermore, an impact mechanism for a hand-held power tool is provided, which has a clutch device which can be engaged and disengaged for establishing and disengaging a drive connection, wherein at least a part of a drive bearing is configured to be able to Flip from an idle position to an impact position.

Description of drawings

Further advantages of the invention are given in the following description of the drawings. An exemplary embodiment of the invention is shown in the drawing. The drawings, description and other application documents contain numerous combinations of features. Professional technicians can separate these features and make other combinations with practical significance in order to achieve specific goals.

The picture shows:

Fig. 1 is a partial sectional view of a preferred hand-held power tool,

Fig. 2 is a cross-sectional view of a preferred impact mechanism with drive mechanism and clutch when it is in the impact position,

Figure 3 Device in idle position,

Figure 4 The device in Figure 3 is in the transition from the idle position to the impact position,

Figure 5 The device in Figure 3 is in the impact position.

Detailed ways

FIG. 1 shows a partial section of a preferred hand-held power tool 70 with a hammer mechanism 40 and a clutch device 20 . A tool 74 is inserted in a tool holder 72 of the hand-held power tool 70 , which machines a machining surface in a machining direction 76 . The operator holds a bow-shaped handle 78 and a handle 80 protruding vertically downwards of the hand power tool 70 .

FIG. 2 shows a section through a preferred percussion mechanism 40 for use in hammer drills and/or chisel hammers with an electric motor not shown in detail. The percussion mechanism 40 has a drive designed as a swivel drive and a clutch 20 . The electric motor therein has a rotor shaft 10, while the drive mechanism is located in the impact position. A pinion 12 is formed on the rotor shaft 10 and meshes with a spur gear 14 on an intermediate shaft 16 arranged parallel to the rotor shaft 10 . On a side facing a not shown tool holder, the countershaft 16 has a shaped gear 66 via which the countershaft 16 meshes with a not shown gear mounted on the hammer tube 64 .

On the intermediate shaft 16 , between the spur gear 14 and the gear wheel 66 , the percussion mechanism 40 is rotatably supported by means of a drive bearing 18 , which includes the pivot drive with a pivot pin 46 . On the outer circumference of the drive bearing 18, a ball circuit 42 is arranged, on which the balls are guided. The ball orbit 42 is perpendicular to the longitudinal axis 60 of the drive bearing 18 and, like the longitudinal axis 60 , is pivoted by an angle α relative to the rotational axis 90 of the intermediate shaft 16 in the impact position. Therefore, when the intermediate shaft 16 rotates, the swing pin 46 performs a swing motion. Through this pivoting movement, as explained above, an air cushion is compressed in the cylinder tube 50 and an impulse is transmitted via a striking pin 52 to a tool, not shown.

Furthermore, a clutch device 20 is supported on the intermediate shaft 16 , which can be engaged and disengaged in order to establish or disengage the drive connection of the percussion mechanism 40 . On the side of the gear wheel 66 facing away from the tool holder, the clutch device 20 has a clutch element 24 , which is supported on the countershaft 16 and is axially displaceable and non-rotatable relative to the countershaft. On its end facing the tool holder, the clutch element 24 has a circumferential groove 36 which extends between an inner bead 32 designed as an annular bead and an outer bead 34 formed as an annular bead. The inner protrusion 32 formed by the annular protrusion has a larger radius than the outer protrusion 34 formed by the annular protrusion. A locking ring 68 surrounding the hammer tube 64 is sunk in the groove 36 . The locking ring is fixed axially between two grooves on the hammer tube 64 . The axial movement of the hammer tube 64 will thus be transmitted to the clutch element 24 . A tool (not shown) which is axially displaceable is fixed in the hammer tube 64 in a rotationally fixed manner.

The coupling element 24 is surrounded by a sliding sleeve 28 which has a projection 62 in the form of an annular projection on the side facing the spur gear 14 . Between the protrusion 62 of the sliding sleeve 28 configured as an annular protrusion and the inner protrusion 32 of the clutch element 24 configured as an annular protrusion, a lost motion spring 30 is arranged, the axial length of which is in the air. It is the largest in the running position and the smallest in the impact position.

An outer end surface of this projection 62 designed as an annular projection of the sliding sleeve 28 bears against the drive bearing 18 , wherein the drive bearing 18 is positively connected to the spur gear 14 via a toothed coupling 54 .

On its side facing the spur gear 14 , the clutch element 24 has a cone 26 whose diameter decreases in the direction of the spur gear 14 . With this cone 26 the coupling element 24 forms a support 56 for the drive bearing 18 . The angle α between an inclined outer surface 82 and a bored straight inner surface 84 of the clutch element 24 is preferably between 5° and 85°, and particularly preferably between 10° and 20°. This angle α is also equal to the inclination α between the longitudinal axis 60 of the drive bearing 18 and the axis of rotation 90 .

If the intermediate shaft 16 turns, the drive bearing 18 is mounted on the cone 26 and rotates about the axis of rotation 90 of the intermediate shaft 16 . The corresponding surface 58 of the drive bearing 18 forms an inner cone with an opening angle of 2α, while the support 56 forms an outer cone with the cone 26 and an opening angle of 2α. A rotational drive of the clutch element 24 is implemented in a form-fitting manner by means of ball rolling bodies 24 which are fixedly connected to the countershaft 16 and are arranged between the clutch element 24 and the countershaft 16 .

The hammer tube 64 is axially displaceable relative to the free-running spring 30 and is actuated by the operator in such a way that the hand-held power tool and thus the tool, in particular a drilling tool and/or chisel tool, is pressed against the work surface as required on the removed material. This movement is transmitted to the hammer tube 64 and to the clutch member 24 by the impact peg 52 supported in the hammer tube 64 in the usual manner. The cone 26 of the coupling element 24 is thus covered by a corresponding inner surface 58 on the drive bearing 18, which will be described in more detail in the figures below.

In FIGS. 3 to 5, a detailed view of the device shown in FIG. 2 is shown in the idling position, in the transition from the idling position to the impact position, and in the impact position, respectively. Components that remain essentially unchanged are in principle identified with the same reference numerals. Furthermore, as far as features and functions remain unchanged, reference is made to the description of the preceding figures.

The drive bearing 18 is shown in FIG. 3 in a idling position, in which it is in a position substantially perpendicular to the countershaft 16 , where the longitudinal axis 60 coincides with the axis of rotation 90 of the countershaft 16 .

The drive bearing 18 has a substantially cylindrical outer contour. On the side facing the spur gear 14 , the dog coupling 54 is provided with the spur gear 14 , wherein a drive element, not shown in detail, is sunk into the spur gear 14 . Diagonally opposite the side facing the clutch element 24 , the drive bearing 18 has a bevel 86 at the transition from the cylindrical circumference of the drive bearing 18 to a bore with the surface 58 .

Inside the drive bearing 18 are provided bores with faces 58 and 88 at an angle to each other, which generally intersect at a center point of the drive bearing 18 and substantially at a point relative to the center point of the drive bearing 18. Symmetrical setting. The surface 58 forms the inner cone mentioned in FIG. 2 which rests on a cone 26 on a coupling element 24 . In the idling position, the part of the inner cone of the surface 58 facing away from the hammer tube 64 rests on the intermediate shaft 16, the part facing the hammer tube 64 rises from the intermediate shaft 16, while the axially adjacent part of the surface 88 Parts stand up from the intermediate shaft 16 , and the part of the surface 88 which is close to the hammer tube 64 rests against the intermediate shaft 16 .

The coupling element 24 is located at a position at the greatest distance relative to the drive bearing 18 ; the freewheel spring 30 has the greatest axial length. The sliding sleeve 28 rests with its projection 62 configured as an annular projection against the lower part of the drive bearing 18 facing away from the hammer tube 64 .

If the spur gear 14 turns, the drive bearing 18 is driven by the spur gear 14 via a form-fit connection, but not in an oscillating movement. Instead, the pivot pin 46 , which protrudes into the hammer tube (not shown), remains stationary due to the straightly extending ball orbit 42 because the longitudinal axis 60 coincides with the axis of rotation 90 .

If a tool, not shown, is pressed against the machining surface so that the clutch element 24 moves axially towards the drive bearing 18 , as shown in FIG. 4 , the drive bearing 18 starts to pivot towards the clutch element 24 . This inversion is facilitated by the oscillating motion that begins to occur. The freewheeling spring 30 is compressed between the inner annular projection 32 of the clutch element 24 moving axially towards the spur gear 14 and the projection 62 of the sliding sleeve 28 configured as an annular projection and is formed as an annular projection The projection 62 of the drive bearing 18 comes into contact with the ramp 86 . The dog coupling 54 between the drive bearing 18 and the spur gear 14 is reinforced.

If the clutch element 24 is moved into the impact position, as shown in FIG. 5 , the cone 26 supports the drive bearing 18 . At the same time, the drive bearing 18 is sunk to the maximum depth into the spur gear 14, so that the jaw connector forms a secure form-fit connection.

The clutch element 24 forms a support 56 of the drive bearing 18 with the cone 26 at the impact point; the inner cone of the drive bearing 18 rests with a corresponding surface 58 on the cone 26 of the clutch element 24 forming the outer cone. The bevel 86 abuts over a large area on the end face of the annular projection 62 of the sliding sleeve 28 .

code list

10 rotor shaft 50 piston cylinder

12 small gears 52 impact pins

14 spur gears 54 teeth connectors

16 intermediate shafts 56 supports

18 drive bearing 58 corresponding surface

20 clutch device 60 longitudinal axis

22 rolling elements 62 protrusions

24 clutch element 64 hammer tube

26 conical 66 gears

28 sliding sleeve 68 locking ring

30 airborne springs 70 hand-held machine tools

32 bumps 72 tool holders

34 bumps 74 knives

36 slots 76 processing directions

40 impact mechanism 78 handle

42-ball orbital track 80 handles

44 balls 82 sloped outer surfaces

46 swing pin 84 inner surface

86 slopes 90 axis of rotation

88 surface α angle

Claims (11)

1. hand held power machine, have a beater mechanism (40) and an arrangement of clutch (20), this arrangement of clutch to be connected (54) with the driving that disconnects beater mechanism (40) and can be engaged and to separate in order to set up, and it is characterized by: at least one section construction of a driving bearing (18) becomes can be turned on the impact position from a dry run position.

2. hand held power machine as claimed in claim 1 is characterized by: clutching member (24) is a support (56) of subregion formation driving bearing (18) at least on an impact position.

3. hand held power machine as claimed in claim 1 or 2 is characterized by: a support (56) circular cone type of this driving bearing (18) shrinks ground and constitutes.

4. as one of above-mentioned claim described hand held power machine, it is characterized by: this driving bearing (18) has a corresponding face (58) of the support (56) with this driving bearing (18).

5. as the described hand held power machine of one of above-mentioned claim, it is characterized by: this driving bearing (18) at least on described impact position the side with the support (56) that deviates from driving bearing (18) sink in the roller gear that is driven (14) by a jaw connector (54).

6. as the described hand held power machine of one of claim 2 to 5, it is characterized by: clutching member (24) is placed on the jackshaft (16).

7. hand held power machine as claimed in claim 6 is characterized by: the rotating driving device of settling rolling element (a 22) formation that is connected with jackshaft (16) by some fixed-site ground between clutching member (24) and jackshaft (16).

8. as the described hand held power machine of one of claim 2 to 7, it is characterized by: clutching member (24) connects in the axial direction rigidly with a hammer pipe (64).

9. as the described hand held power machine of one of claim 2 to 8, it is characterized by: between a slippage sleeve pipe (28) and clutching member (24), settling a dry run spring (30).

10. as one of above-mentioned claim described hand held power machine, it is characterized by: driving bearing (18) has a capable track of ball (42), and it stretches perpendicular to the longitudinal axis (60) of driving bearing (18).

11. beater mechanism, be used for hand held power machine (70), has an arrangement of clutch (20), this arrangement of clutch to be connected (54) and can be engaged and to separate in order to set up with disconnecting driving, and it is characterized by: at least a portion of a driving bearing (18) is configured to and can be turned on the impact position from a dry run position.

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